Showing papers by "D. J. Taylor published in 2020"
TL;DR: Lux-ZEPLIN (LZ) as mentioned in this paper is a next-generation dark matter direct detection experiment that will operate 4850 feet underground at the Sanford Underground Research Facility (SURF) in Lead, South Dakota, USA using a two-phase xenon detector with an active mass of 7 tonnes.
Abstract: LUX-ZEPLIN (LZ) is a next-generation dark matter direct detection experiment that will operate 4850 feet underground at the Sanford Underground Research Facility (SURF) in Lead, South Dakota, USA Using a two-phase xenon detector with an active mass of 7 tonnes, LZ will search primarily for low-energy interactions with weakly interacting massive particles (WIMPs), which are hypothesized to make up the dark matter in our galactic halo In this paper, the projected WIMP sensitivity of LZ is presented based on the latest background estimates and simulations of the detector For a 1000 live day run using a 56-tonne fiducial mass, LZ is projected to exclude at 90% confidence level spin-independent WIMP-nucleon cross sections above 14 × 10-48cm2 for a 40 GeV/c2 mass WIMP Additionally, a 5σ discovery potential is projected, reaching cross sections below the exclusion limits of recent experiments For spin-dependent WIMP-neutron(-proton) scattering, a sensitivity of 23 × 10−43 cm2 (71 × 10−42 cm2) for a 40 GeV/c2
mass WIMP is expected With underground installation well underway, LZ is on track for commissioning at SURF in 2020
231 citations
11 Feb 2020-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: The design and assembly of the LUX-ZEPLIN experiment, a direct detection search for cosmic WIMP dark matter particles, is described and its key design features and requirements are described.
Abstract: We describe the design and assembly of the LUX-ZEPLIN experiment, a direct detection search for cosmic WIMP dark matter particles. The centerpiece of the experiment is a large liquid xenon time projection chamber sensitive to low energy nuclear recoils. Rejection of backgrounds is enhanced by a Xe skin veto detector and by a liquid scintillator Outer Detector loaded with gadolinium for efficient neutron capture and tagging. LZ is located in the Davis Cavern at the 4850’ level of the Sanford Underground Research Facility in Lead, South Dakota, USA. We describe the major subsystems of the experiment and its key design features and requirements.
145 citations
Stanford University1, University of Wisconsin-Madison2, Imperial College London3, South Dakota School of Mines and Technology4, University of California, Davis5, University of Liverpool6, University of California, Berkeley7, Lawrence Livermore National Laboratory8, Lawrence Berkeley National Laboratory9, Yale University10, University of Coimbra11, University of South Dakota12, Brown University13, University of Rochester14, University College London15, University of Maryland, College Park16, University of California, Santa Barbara17, University of Massachusetts Amherst18, University of Sheffield19, University of Edinburgh20, Texas A&M University21, University at Albany, SUNY22, California State University, Stanislaus23, Pennsylvania State University24
TL;DR: In this paper, a systematic investigation of the electron pathologies observed in the LUX dark matter experiment is presented, including photoionization and photoelectric effect induced by the xenon luminescence, delayed emission of electrons trapped under the liquid surface, capture and release of drifting electrons by impurities and grid electron emission.
Abstract: Dual-phase xenon detectors, as currently used in direct detection dark matter experiments, have observed elevated rates of background electron events in the low energy region. While this background negatively impacts detector performance in various ways, its origins have only been partially studied. In this paper we report a systematic investigation of the electron pathologies observed in the LUX dark matter experiment. We characterize different electron populations based on their emission intensities and their correlations with preceding energy depositions in the detector. By studying the background under different experimental conditions, we identified the leading emission mechanisms, including photoionization and the photoelectric effect induced by the xenon luminescence, delayed emission of electrons trapped under the liquid surface, capture and release of drifting electrons by impurities, and grid electron emission. We discuss how these backgrounds can be mitigated in LUX and future xenon-based dark matter experiments.
38 citations
Stanford University1, University of Wisconsin-Madison2, Imperial College London3, South Dakota School of Mines and Technology4, University of California, Davis5, University of Liverpool6, University of California, Berkeley7, Lawrence Livermore National Laboratory8, Yale University9, Lawrence Berkeley National Laboratory10, University of Coimbra11, University of South Dakota12, Brown University13, University of Rochester14, University College London15, University of Maryland, College Park16, University of California, Santa Barbara17, University of Massachusetts Amherst18, University of Sheffield19, University of Edinburgh20, Texas A&M University21, University at Albany, SUNY22, California State University, Stanislaus23, Pennsylvania State University24
TL;DR: Akerib et al. as discussed by the authors presented a comprehensive analysis of electronic recoil vs nuclear recoil discrimination in liquid/gas xenon time projection chambers, using calibration data from the 2013 and 2014-2016 runs of the Large Underground Xenon experiment.
Abstract: Author(s): Akerib, DS; Alsum, S; Araujo, HM; Bai, X; Balajthy, J; Baxter, A; Bernard, EP; Bernstein, A; Biesiadzinski, TP; Boulton, EM; Boxer, B; Bras, P; Burdin, S; Byram, D; Carmona-Benitez, MC; Chan, C; Cutter, JE; De Viveiros, L; Druszkiewicz, E; Fan, A; Fiorucci, S; Gaitskell, RJ; Ghag, C; Gilchriese, MGD; Gwilliam, C; Hall, CR; Haselschwardt, SJ; Hertel, SA; Hogan, DP; Horn, M; Huang, DQ; Ignarra, CM; Jacobsen, RG; Jahangir, O; Ji, W; Kamdin, K; Kazkaz, K; Khaitan, D; Korolkova, EV; Kravitz, S; Kudryavtsev, VA; Leason, E; Lenardo, BG; Lesko, KT; Liao, J; Lin, J; Lindote, A; Lopes, MI; Manalaysay, A; Mannino, RL; Marangou, N; McKinsey, DN; Mei, DM; Moongweluwan, M; Morad, JA; Murphy, ASJ; Naylor, A; Nehrkorn, C; Nelson, HN; Neves, F; Nilima, A; Oliver-Mallory, KC; Palladino, KJ; Pease, EK; Riffard, Q; Rischbieter, GRC; Rhyne, C; Rossiter, P; Shaw, S; Shutt, TA; Silva, C; Solmaz, M; Solovov, VN; Sorensen, P; Sumner, TJ; Szydagis, M; Taylor, DJ; Taylor, R; Taylor, WC; Tennyson, BP; Terman, PA; Tiedt, DR; To, WH; Tvrznikova, L; Utku, U | Abstract: We present a comprehensive analysis of electronic recoil vs nuclear recoil discrimination in liquid/gas xenon time projection chambers, using calibration data from the 2013 and 2014-2016 runs of the Large Underground Xenon experiment. We observe strong charge-to-light discrimination enhancement with increased event energy. For events with S1=120 detected photons, i.e., equivalent to a nuclear recoil energy of ∼100 keV, we observe an electronic recoil background acceptance of l10-5 at a nuclear recoil signal acceptance of 50%. We also observe modest electric field dependence of the discrimination power, which peaks at a field of around 300 V/cm over the range of fields explored in this study (50-500 V/cm). In the weakly interacting massive particle search region of S1=1-80 phd, the minimum electronic recoil leakage we observe is (7.3±0.6)×10-4, which is obtained for a drift field of 240-290 V/cm. Pulse shape discrimination is utilized to improve our results, and we find that, at low energies and low fields, there is an additional reduction in background leakage by a factor of up to 3. We develop an empirical model for recombination fluctuations which, when used alongside the Noble Element Scintillation Technique simulation package, correctly reproduces the skewness of the electronic recoil data. We use this updated simulation to study the width of the electronic recoil band, finding that its dominant contribution comes from electron-ion recombination fluctuations, followed in magnitude of contribution by fluctuations in the S1 signal, fluctuations in the S2 signal, and fluctuations in the total number of quanta produced for a given energy deposition.
30 citations
TL;DR: In this paper, the authors exploit the double photoelectron emission effect observed in some photomultiplier models at vacuum ultraviolet wavelengths to lower the energy threshold of liquid xenon time projection chambers.
Abstract: We present a novel analysis technique for liquid xenon time projection chambers that allows for a lower threshold by relying on events with a prompt scintillation signal consisting of single detected photons. The energy threshold of the LUX dark matter experiment is primarily determined by the smallest scintillation response detectable, which previously required a twofold coincidence signal in its photomultiplier arrays, enforced in data analysis. The technique presented here exploits the double photoelectron emission effect observed in some photomultiplier models at vacuum ultraviolet wavelengths. We demonstrate this analysis using an electron recoil calibration dataset and place new constraints on the spin-independent scattering cross section of weakly interacting massive particles (WIMPs) down to 2.5 GeV/c2 WIMP mass using the 2013 LUX dataset. This new technique is promising to enhance light WIMP and astrophysical neutrino searches in next-generation liquid xenon experiments.
26 citations
TL;DR: Lux-ZEPLIN (LZ) is a second-generation direct dark matter experiment with spin-independent WIMP-nucleon scattering sensitivity above $1.4 \times 10-48}$ cm$^{2}$ as discussed by the authors.
Abstract: LUX-ZEPLIN (LZ) is a second-generation direct dark matter experiment with spin-independent WIMP-nucleon scattering sensitivity above $1.4 \times 10^{-48}$ cm$^{2}$ for a WIMP mass of 40 GeV/c$^{2}$ and a 1000 d exposure. LZ achieves this sensitivity through a combination of a large 5.6 t fiducial volume, active inner and outer veto systems, and radio-pure construction using materials with inherently low radioactivity content. The LZ collaboration performed an extensive radioassay campaign over a period of six years to inform material selection for construction and provide an input to the experimental background model against which any possible signal excess may be evaluated. The campaign and its results are described in this paper. We present assays of dust and radon daughters depositing on the surface of components as well as cleanliness controls necessary to maintain background expectations through detector construction and assembly. Finally, examples from the campaign to highlight fixed contaminant radioassays for the LZ photomultiplier tubes, quality control and quality assurance procedures through fabrication, radon emanation measurements of major sub-systems, and bespoke detector systems to assay scintillator are presented.
22 citations
TL;DR: Lux-ZEPLIN (LZ) as mentioned in this paper is a second-generation direct dark matter experiment with spin-independent WIMP-nucleon scattering sensitivity above 1.4 \times 10-48\, {\hbox {cm}}^{2}
Abstract: LUX-ZEPLIN (LZ) is a second-generation direct dark matter experiment with spin-independent WIMP-nucleon scattering sensitivity above $${1.4 \times 10^{-48}}\, {\hbox {cm}}^{2}$$
for a WIMP mass of $${40}\, \hbox {GeV}/{\hbox {c}}^{2}$$
and a $${1000}\, \hbox {days}$$
exposure. LZ achieves this sensitivity through a combination of a large $${5.6}\, \hbox {t}$$
fiducial volume, active inner and outer veto systems, and radio-pure construction using materials with inherently low radioactivity content. The LZ collaboration performed an extensive radioassay campaign over a period of six years to inform material selection for construction and provide an input to the experimental background model against which any possible signal excess may be evaluated. The campaign and its results are described in this paper. We present assays of dust and radon daughters depositing on the surface of components as well as cleanliness controls necessary to maintain background expectations through detector construction and assembly. Finally, examples from the campaign to highlight fixed contaminant radioassays for the LZ photomultiplier tubes, quality control and quality assurance procedures through fabrication, radon emanation measurements of major sub-systems, and bespoke detector systems to assay scintillator are presented.
21 citations
TL;DR: Akerib et al. as discussed by the authors presented the results of a direct detection search for mirror dark matter interactions, using data collected from the Large Underground Xenon experiment during 2013, with an exposure of 95 live-days×118 kg.
Abstract: Author(s): Akerib, DS; Alsum, S; Araujo, HM; Bai, X; Balajthy, J; Baxter, A; Bernard, EP; Bernstein, A; Biesiadzinski, TP; Boulton, EM; Boxer, B; Bras, P; Burdin, S; Byram, D; Carmona-Benitez, MC; Chan, C; Cutter, JE; De Viveiros, L; Druszkiewicz, E; Fan, A; Fiorucci, S; Gaitskell, RJ; Ghag, C; Gilchriese, MGD; Gwilliam, C; Hall, CR; Haselschwardt, SJ; Hertel, SA; Hogan, DP; Horn, M; Huang, DQ; Ignarra, CM; Jacobsen, RG; Jahangir, O; Ji, W; Kamdin, K; Kazkaz, K; Khaitan, D; Korolkova, EV; Kravitz, S; Kudryavtsev, VA; Leason, E; Lenardo, BG; Lesko, KT; Liao, J; Lin, J; Lindote, A; Lopes, MI; Manalaysay, A; Mannino, RL; Marangou, N; Marzioni, MF; McKinsey, DN; Mei, DM; Moongweluwan, M; Morad, JA; Murphy, ASJ; Naylor, A; Nehrkorn, C; Nelson, HN; Neves, F; Nilima, A; Oliver-Mallory, KC; Palladino, KJ; Pease, EK; Riffard, Q; Rischbieter, GRC; Rhyne, C; Rossiter, P; Shaw, S; Shutt, TA; Silva, C; Solmaz, M; Solovov, VN; Sorensen, P; Sumner, TJ; Szydagis, M; Taylor, DJ; Taylor, R; Taylor, WC; Tennyson, BP; Terman, PA; Tiedt, DR; To, WH; Tripathi, M | Abstract: We present the results of a direct detection search for mirror dark matter interactions, using data collected from the Large Underground Xenon experiment during 2013, with an exposure of 95 live-days×118 kg. Here, the calculations of the mirror electron scattering rate in liquid xenon take into account the shielding effects from mirror dark matter captured within the Earth. Annual and diurnal modulation of the dark matter flux and atomic shell effects in xenon are also accounted for. Having found no evidence for an electron recoil signal induced by mirror dark matter interactions we place an upper limit on the kinetic mixing parameter over a range of local mirror electron temperatures between 0.1 and 0.9 keV. This limit shows significant improvement over the previous experimental constraint from orthopositronium decays and significantly reduces the allowed parameter space for the model. We exclude mirror electron temperatures above 0.3 keV at a 90% confidence level, for this model, and constrain the kinetic mixing below this temperature.
17 citations
SLAC National Accelerator Laboratory1, Stanford University2, University of Wisconsin-Madison3, Imperial College London4, South Dakota School of Mines and Technology5, University of California, Davis6, University of Liverpool7, University of California, Berkeley8, Lawrence Livermore National Laboratory9, Lawrence Berkeley National Laboratory10, Yale University11, University of Coimbra12, University of South Dakota13, Pennsylvania State University14, Brown University15, University of Rochester16, University College London17, University of Maryland, College Park18, University of California, Santa Barbara19, University of Massachusetts Amherst20, University of Sheffield21, University of Edinburgh22, Texas A&M University23, State University of New York System24, California State University, Stanislaus25
TL;DR: Deviveiros et al. as mentioned in this paper used NEST v2.0 to reproduce the scintillation and ionization response of a dual-phase liquid and gaseous xenon time projection chamber.
Abstract: Author(s): Deviveiros, L; Akerib, DS; Alsum, S; Araujo, HM; Bai, X; Balajthy, J; Baxter, A; Bernard, EP; Bernstein, A; Biesiadzinski, TP; Boulton, EM; Boxer, B; Bras, P; Burdin, S; Byram, D; Carmona-Benitez, MC; Chan, C; Cutter, JE; Druszkiewicz, E; Fan, A; Fiorucci, S; Gaitskell, RJ; Ghag, C; Gilchriese, MGD; Gwilliam, C; Hall, CR; Haselschwardt, SJ; Hertel, SA; Hogan, DP; Horn, M; Huang, DQ; Ignarra, CM; Jacobsen, RG; Jahangir, O; Ji, W; Kamdin, K; Kazkaz, K; Khaitan, D; Korolkova, EV; Kravitz, S; Kudryavtsev, VA; Leason, E; Lenardo, BG; Lesko, KT; Liao, J; Lin, J; Lindote, A; Lopes, MI; Manalaysay, A; Mannino, RL; Marangou, N; Marzioni, MF; McKinsey, DN; Mei, DM; Moongweluwan, M; Morad, JA; Murphy, ASJ; Naylor, A; Nehrkorn, C; Nelson, HN; Neves, F; Nilima, A; Oliver-Mallory, KC; Palladino, KJ; Pease, EK; Riffard, Q; Rischbieter, GRC; Rhyne, C; Rossiter, P; Shaw, S; Shutt, TA; Silva, C; Solmaz, M; Solovov, VN; Sorensen, P; Sumner, TJ; Szydagis, M; Taylor, DJ; Taylor, R; Taylor, WC; Tennyson, BP; Terman, PA; Tiedt, DR; To, WH; Tripathi, M | Abstract: We report here methods and techniques for creating an improved model that reproduces the scintillation and ionization response of a dual-phase liquid and gaseous xenon time projection chamber. Starting with the recent release of the Noble Element Simulation Technique (NEST v2.0), electronic recoil data from the β decays of 3H and 14C in the Large Underground Xenon (LUX) detector were used to tune the model, in addition to external data sets that allow for extrapolation beyond the LUX data-taking conditions. This paper also presents techniques used for modeling complicated temporal and spatial detector pathologies that can adversely affect data using a simplified model framework. The methods outlined in this report show an example of the robust applications possible with NEST v2.0 framework and how it can be modified to produce a final, detector-specific, electronic recoil model. This example provides the final model for LUX and detector parameters that will used in the new analysis package, the LUX Legacy Analysis Monte Carlo Application (LLAMA), for accurate reproduction of the LUX data. As accurate background reproduction is crucial for the success of rare-event searches, such as dark matter direct detection experiments, the techniques outlined here can be used in other single-phase and dual-phase xenon detectors to assist with accurate ER background reproduction.
12 citations
Stanford University1, SLAC National Accelerator Laboratory2, University of Wisconsin-Madison3, Imperial College London4, South Dakota School of Mines and Technology5, University of California, Davis6, University of Liverpool7, University of California, Berkeley8, Lawrence Livermore National Laboratory9, Yale University10, Lawrence Berkeley National Laboratory11, University of Coimbra12, University of South Dakota13, Pennsylvania State University14, Brown University15, University of Rochester16, University College London17, University of Maryland, College Park18, University of California, Santa Barbara19, University of Massachusetts Amherst20, University of Sheffield21, University of Edinburgh22, Texas A&M University23, State University of New York System24, California State University, Stanislaus25
TL;DR: Akerib et al. as mentioned in this paper reported on the search for this process in 124Xe and 126Xe using the full exposure of the large underground xenon (LUX) experiment, in a total of 27769.
Abstract: Author(s): Akerib, DS; Alsum, S; Araujo, HM; Bai, X; Balajthy, J; Baxter, A; Bernard, EP; Bernstein, A; Biesiadzinski, TP; Boulton, EM; Boxer, B; Bras, P; Burdin, S; Byram, D; Carmona-Benitez, MC; Chan, C; Cutter, JE; De Viveiros, L; Druszkiewicz, E; Fan, A; Fiorucci, S; Gaitskell, RJ; Ghag, C; Gilchriese, MGD; Gwilliam, C; Hall, CR; Haselschwardt, SJ; Hertel, SA; Hogan, DP; Horn, M; Huang, DQ; Ignarra, CM; Jacobsen, RG; Jahangir, O; Ji, W; Kamdin, K; Kazkaz, K; Khaitan, D; Korolkova, EV; Kravitz, S; Kudryavtsev, VA; Leason, E; Lenardo, BG; Lesko, KT; Liao, J; Lin, J; Lindote, A; Lopes, MI; Manalaysay, A; Mannino, RL; Marangou, N; Marzioni, MF; McKinsey, DN; Mei, DM; Moongweluwan, M; Morad, JA; Murphy, ASJ; Naylor, A; Nehrkorn, C; Nelson, HN; Neves, F; Nilima, A; Oliver-Mallory, KC; Palladino, KJ; Pease, EK; Riffard, Q; Rischbieter, GRC; Rhyne, C; Rossiter, P; Shaw, S; Shutt, TA; Silva, C; Solmaz, M; Solovov, VN; Sorensen, P; Sumner, TJ; Szydagis, M; Taylor, DJ; Taylor, R; Taylor, WC; Tennyson, BP; Terman, PA; Tiedt, DR; To, WH; Tripathi, M | Abstract: Two-neutrino double electron capture is a process allowed in the standard model of particle physics. This rare decay has been observed in 78Kr, 130Ba and more recently in 124Xe. In this publication we report on the search for this process in 124Xe and 126Xe using the full exposure of the large underground xenon (LUX) experiment, in a total of 27769.5 kg-days. No evidence of a signal was observed, allowing us to set 90% C.L. lower limits for the half-lives of these decays of 2.0 × 1021 years for 124Xe and 1.9 × 1021 years for 126Xe.
3 citations